Rapid DNA sequencing is helping doctors treat critically ill infants in days rather than weeks.

Adding new diseases to screening rosters inevitably means adding to the cost of tests for newborns, which run about 0 to 0, depending on the state. The tests are typically covered by insurers or Medicaid, but funding in some states comes from the health department’s budget. Adding SMA would cost anywhere between 10 cents and , according to a report issued by the US government in March.

ALD, meanwhile, was recommended for addition to the federal list of screenings by the HHS secretary in 2015, but states have been slow to adopt the change. Only a handful test for it today.

“It’s a nightmare,” says Maria Kefalas, a patient advocate and founder of the Calliope Joy Foundation, which raises money to help children with leukodystrophy. “Lobbying states one by one is ridiculous.” Her daughter was diagnosed at age two with a rare genetic brain disorder called metachromatic leukodystrophy. An experimental gene therapy available at a single site in Milan, Italy, has saved children with the otherwise terminal disease—but only if it’s given early enough. London-based Orchard Therapeutics is working on commercializing the therapy.

To know or not to know

Not everyone thinks screening newborns for more diseases is a good idea. The results could cause extra anxiety for parents, and there’s the possibility of false positives.

A pilot program in Massachusetts that’s testing newborns for SMA, for example, showed that a baby had the disease—but a few months later it turned out to be a false alarm.

“Can you imagine what that couple went through?” says Kathryn Swoboda, a pediatric neurologist at Massachusetts General Hospital, who is involved in the pilot program. “It’s really tough on families.”

Not all parents want to find out if their child will go on to develop a serious disease, especially if, as in some cases, its onset is years away. SMA is a prime example: there are five types, and while most cases appear within the first six to 18 months of life, one type doesn’t come on until adulthood. Similarly, onset for cerebral ALD, which the Bluebird therapy is designed to treat, can occur when a child is anywhere between two and 10 years old. Swoboda says knowing this could make it harder for parents to bond with a child.

Still, people like Kefalas think the benefits often outweigh the risks. “There are so many ramifications of having this information at birth,” she says, “but for some diseases it seems like a no-brainer.”